1. Field of the Invention
The present invention relates to a blender system that can be adjusted to a plurality of heights.
2. Description of the Background of the Invention
A variable height blender, such as used in industrial applications for example, is known to be useful in order to facilitate easier loading and unloading of mix contents from the blender. In a batch blender, a blender is loaded with a specific amount, or batch, of contents that are to be mixed, the contents are mixed without any contents being added or subtracted from the blender, and when mixing is complete, the contents are removed from the blender. Often, it is desirable to be able to load the contents with the blender at approximately floor level, such as by shoveling contents into the blender by hand, and to be able to unload the contents of the blender into a container that is also at approximately floor level. In order to facilitate easier unloading of the contents, different systems have been developed to raise the blender above floor level so that the contents can be emptied from the blender by gravity into the container at ground level.
In one example, Bohle U.S. Pat. No. 5,090,815 discloses a batch mixer that is carried between two mechanisms for vertically moving the batch mixer up and down between an upper position and a lower position. The moving mechanisms are disclosed as being two vertically oriented fluid cylinder and piston units, such as hydraulic cylinders or pneumatic cylinders, and guides. The cylinder and piston units are designed to positively move the vessel upwardly. The batch mixer has a openable top cover and a discharge outlet in a bottom thereof. In use, the batch mixer is loaded through the open top when the batch mixer is in a lowered position and emptied by gravity through the discharge outlet when the batch mixer is in a raised position. However, Bohle does not provide specific information regarding how the two fluid cylinders are controlled.
In another example, Bongratz U.S. Pat. No. 7,121,715 discloses a batch blender that is carried between two vertically oriented hydraulic lifts such that the hydraulic lifts can move the batch blender up and down to provide easy top loading at floor level and easy gravity discharge into a container placed below the batch blender after the batch blender has been raised. Bongratz '715 teaches that the hydraulic lifts are coordinated in a standard fashion to keep the horizontal axis of the batch blender substantially parallel to the floor in both a discharge position and a loading position. However, Bongratz '715 does not provide explicit detail about how the hydraulic lifts are coordinated.
The inventor of the present application has found that hydraulic lifts and the standard systems for coordinating such hydraulic lifts known previously tend to be complicated and/or can cause unintended and/or undesirable limitations on the vertical travel or stroke of the lifts and the batch blender. Therefore, the inventor has developed a new system that provides advantages over the previously known systems.